A teacher giving a lesson to pupils in a London primary school Photograph: Graham Turner

Children educated at home are twice as likely to be known by social services and four times more likely as young adults to be out of work, education or training than those who go to school, MPs have been told.

MPs on the cross-party select committee for children, schools and families asked the head of a government inquiry into home education and the schools minister to defend calls for tougher rules on parents who teach their children at home.

In his review published in June, Kent's former education director Graham Badman recommended that all home educators register with their local authority. Councils should be given powers to refuse registration if a child is believed to be at risk, he said.

Badman also called for parents to be asked for a 12-month plan detailing what they would be teaching their children.

The review was commissioned to investigate whether the number of children known to social care in some local authorities was disproportionately high relative to the size of their home educating population.

The committee is investigating the review after a backlash from parents who say they have been stigmatised as more likely to be child abusers.

But Badman told the MPs that although "we shouldn't treat home educators with suspicion, we should know that the risk factor is proportionately double".

The review of 74 local authorities had found that while 0.2% of children in the UK population were known to social services, the figure was 0.4% among those who were educated at home.

"I met several who were very accomplished, but we can't say that all children are safe," he said. "I take the view that some people have prospered with home education."

He said that "the percentage of home-educated children who are not in employment, education or training [known as 'neets'] is higher than in the national population".

Of the 1,220 home-educated children studied for the review, 270 were "neets", around 22%. This was more than four times the proportion of neets in the UK population, he said.

Barry Sheerman, the chair of the committee and Labour MP for Huddersfield, said that while there were some "fantastic examples" of home education, there were also some "horror stories". He asked Diana Johnson, the schools minister, whether the review had focused too much on the potential dangers of home education.

Johnson said: "I would say that a lot of the recommendations are about creating a positive relationship between local authorities and home educators. The worrying thing for me is that we don't have a full set of data. We don't know how many children are being home-educated. Because we don't know the number of children, we don't know their educational outcomes."

Badman said that only in extreme circumstances would a local authority forbid a parent from registering as a "home educator". The registration scheme has been accepted in principle by ministers and is under consultation.

The government estimates that around 20,000 children are registered with local authorities as receiving home tuition, but the real number could be closer to 50,000 because parents are obligated to inform the authorities only if they withdraw a child from school, not if they have never been to school.

Fiona Nicholson, of the support group Education Otherwise, has said that a registration scheme would "completely shift the balance of power".

"The state is coming into family life and trying to regulate it. It is an extraordinary invasion of the family," she said.

The committee is to take evidence from home educators tomorrow.

The government now wants a clearer definition of what kind of education should be deemed suitable for children who are educated at home.

Ed Balls, the children's secretary, has said that a review early in 2010 will discuss this.

• This article was amended on 19 October 2009. The headline was changed to reflect more accurately the content of the article about evidence given to the select committee by Graham Badman. The figure of 2.2%, given as the percentage of young people educated at home who were said to be out of work education or training, was changed to 22%.